The present invention relates generally to the application of materials such as fertilizer and chemicals to crops and more specifically to automated machines and methods used for the application of the materials to the crops.
Farmers apply natural and/or synthetic materials to their crops. The material (e.g., fertilizer, seeds, nutrients, water, chemicals, etc.) is typically applied at a single, uniform application rate across a field (i.e., an area). The determination of an optimal application rate for material has often relied upon: a) analysis of soil samples, b) scouting of the physical crop as it grows, c) destructive analysis of tissue or leaf samples of the growing crop, or d) comparative analysis to a “reference strip” of crop planted in that same field and fertilized at a rate known to exceed crop needs. These techniques have resulted in over-application or excess use of material in some areas of the field and under-application and a corresponding deficiency of material in other areas. Both cases often result in the loss of time and money, with a potential to cause irreparable harm.
Instead of applying material at a uniform rate, material can also be applied at a varying rate or multiple, predetermined rates within a field or area of interest. Systems that apply material in this fashion typically use traditional methods to determine an optimal amount of material to be applied to a particular area of a field. Often these techniques have used various reflectance-based technologies in conjunction with a historical database or other reference to determine the appropriate application rates for material. In addition, various reflectance based sensors have been used as a diagnostic tool in this effort.
Material can also be applied in an automated fashion. For example, material can be applied using automated machinery that drives around a field of crops and applies (e.g., sprays or spreads) material onto the crops. To apply an amount of material onto the crops, systems conventionally control one or more applicators (e.g., a sprayer valve and/or a spreader valve) on or attached to the automated machinery (e.g., a tractor).